1. AITEC, 2003. Relazione annuale dell’Associazione Italiana Tecnico Economica Cemento (Annual Report of the Italian Technical and Economic Association of Cement Enterpreneurs), p. 13, http://web.aitecweb.com/AREA%20ECONOMICA/RELAZIONE/RELAZIONE%202003.PDF (in Italian).
2. Alberti, M., Handcock, M., Marzluff, J., Redman, C., Janguo, W., 2006. Biocomplexity II: Urban Landscape Patterns: Complex Dynamics and Emergent Properties. Report to National Science Foundation, July 1, 2005–June 30, 2008, in progress (http://faculty.washington.edu/malberti/).
3. ASSOMET, 2002. Rapporto Annuale della Associazione Nazionale Industrie Metalli non Ferrosi (Yearly Report of the Non Ferrous Metal Industries National Association): http://www.assomet.it/index.php?Mod=2&Doc=245&Lev=3 (in Italian).
4. Assovetro, 2003. Rapporto Annuale della Associazione Nazionale degli Industriali del Vetro Yearly Report of the National Association of Glass Manufacturers. http://www.assovetro.it/3_1_2_import.htm (in Italian).
5. B.C.C., 2003. Bristol's City Council. Bristol's ecological footprint. Quality of Life Report, 2003. http://www.steppingforward.org.uk/ef/swfootprints.htm. Last contact, 28 May 2007.